Closure for building constructions



Aug 17, 1943 MICHELMAN CLOSURE FOR BUILD INC CONSTRUCIIONS '5Sheets-Sheet 2 Filed Dec. 2, 1941 Aug. 17, 1943. N. M ICHELMAN CLOSUREFOR BUILDING CONSTRUCTIONS Filed m;

2, 1941 5 Sheets-Shee 3 ATTOQNEY.

Aug. 17, 1943. N, MICHELMAN CLOSURE FOR BUILDI NG CONSTRUCTIONS 5sheets-sheet 4 Filed Dec. 2, 1941 A'TTORN EY.

Aug. 17, 1943. V N. MICHELMAN CLOSURE FOR BUILDI NG CONSTRUCTIONS FiledDec. 2, 1941 5 Sheets-Sheet 5 a INVENTOR.

ATTORNEY.

Patented Aug. 17, 1943 UNITED STATES PATEN T OFFICE" 2,327,315 oLosUnnFOR BUILDING CONSTRUCTIONS Nathan Michelman, Brooklyn, N. Y. ApplicationDecember 2, 1941, Serial No. 421,272 12 Claims. (01. loo-191) Thisinvention relates generally to closures, as doors, in buildingconstructions and is more particularly directed to improvements in doorsof the so-called sliding types, which are elevated to open position, asemployed in wharves, warehouses and other industrial buildings, toafford access to loading platforms and storage space.

, While the invention, as will be manifest from the description, issusceptible of a wide range of application, in various otherconstructions, including aircraft hangars, garages and similarstructures, where maximum clearances are-essential, for the purposes ofthis disclosure, I have elected to present my invention asit may bepracticed in the construction and operansnior covered or enclosed piersor wharves. However; this is merely illustrative and is not to beconstrued in any sense as a limitation of the scope of utility of myinvention.

In pier or wharf construction, doors of the general type of my inventionare extensively'used to close the openings which are provided inthesides of the pier superstructure} whereby cargo .or freight may betransferred to and from vessels docked alongside the pier, the flooroffthe pier constituting the loading platform to and from which thefreight is usually swung by a crane, operated from the vessel. Tofacilitate'such loading and unloading operations, the openings in thepier wall are usually arranged closetogether; the closures or doorstherefor, which are customarily of the aforesaid sliding type, beingadapted to, be moved upwardly in yarious ways for storage above the headof an opening, so that the maximum head-room is attained. However,

ing the abuse to which they may be subjected in operation by unskilledhands.

Therefore, the primary object of this invention is to provide a dooror'closure of the sliding type referred to and a cooperating door oropeningdefini'ngframe for use in wharf, warehouse and use of suchdevices, especially in the erection and the advantages of the maximumhead-room or clearance are, to an extent, offset by the limitations tothe movement of the boom of the crane, which are presented by the sideframes or jambs of the doorways O-r openings, in'm-any instances itbeing necessary to deposit the freight on'the apron of the pierbefore'an opening, or just within the opening, where thesuperstructureis flush with the stringpiece of the pier, or removal tothe interior of the wharf by stevedores. This, obviously, slows anunloading operation and the same, of course, applied to leading, thefreight being moved by hand to a position within the opening or justbeyond, to be picked uplbythe crane.

Further, the door constructionsand their opcrating mechanisms are not ofthat simple yet rugged design which is requisite to'the performance oftheir primary function and at the same time insure dependable operation,notwithstanduse of piers or wharves.

More specifically, it is an important object of this invention toprovide a slidable door, construc tion, as aforesaid, anddoorway-forming means, with which the door coacts to form a closure,having movable side frame members or socalled J'ambs, which normallyfunction to guidethe door in its closing movement and retainlitin closedposition, but which, when" the door 'is raised to its open position, areactuatable to a position above the head-line of the'fram of the opening,to present an opening having a span in excess of the normal width of thedoor frame and the door matable therewith. "Thus, where a series ofdoors, with their respective doorways, are juxtaposed along the side ofa wharf or building, the entire side of the wharf or building may befree of vertical obstructions between the headline of the doorways oropenings and the flooror'platform of the pier, affording a boom of acrane a virtually unlimited freedom of movement in swinging freight intothe pier shed, for deposit in positions which, because of theobstructions offered by the fixed doorways of existing constructions,are far beyond the effective zone of operation of the boom. I Anotherimportant object of this invention is to provide a door construction inwhich a door embodying upper and lower sections of the requisite ruggedconstruction, may be readilyoperated by the unskilled tog open andclosed positions, with the expenditure of a minimum of actuatingenergy'and'with-a degree of dependability that insures ehicient serviceand low maintenance costs;

Other objects and advantages flowing from the practicing of my inventionwill become'evident as the description proceeds, not only as employed inwharf construction and operation, but in other appllcationsto which itreadily lends itself, as hereinbeforepointed out.

" For the purpose of this disclosure, in the accompanying drawings,Lhaveshown a preferred embodiment of my improved door constructioninvention, showing schematically the upper and lower series of doors inclosed position.

Figure 2 is a view similar to Figure 1, in which the doors of both deckshave been raised or elevated, with the doorway frame members of theupper deck in their normal positions, while those of the lower deck arevariously shown as raised and in movement to the latter position.

Figure 3 is a rear elevation of a door of a.

series, illustrating the actuating and control mechanism. ,7

Figure 4 is a side elevation, partly in section, showing therelationship of the upper and lower sections of a door in closedposition.

Figure 5 is a view similar to Figure 4, in which the two door sectionsare 'in registration for movement as a unit to their stowedposition, thelatter and an intermediate position in the movement of the mated doorsections, being shown in dotted lines. V

Figure 6 is an enlarged sectional detail of the mounting for one end ofa torsion spring, a component of the actuating mechanism.

Figure '7 is a detail of the mounting of the opposite end of the springof the preceding figure, showing the cable-receiving drum.

Figure 8 is a detail view, partly in section, of a tension spring andcooperating means function therewith, as, control media. I

Fig. 9 is a horizontal crOss-sectionlof the guide roller of the lowersection of the door.

Figure 10 is a top plan view, partlyin section, along lines lU-IE! ofFigure 5, showing the guide roller of the upper section and the meansfor interconnecting the two door sections. v V, v Figure 11 is a view inelevation, showinga shiftablevertical'member of the doorway frame andcooperating door track, together with the means for actuating suchmember to and from normal position, the extreme raised and anintermediate position of said .member being indicated in dotted lines.

Figure 12 is a detail of the hinge connection between the door framemember and the door track thereabove. v

Figure 13 is a detail, partly in section, along line l3-l3 of Figure 11of the hanger and carriage which function in the movement of the doorframe member; and.

Figures 14 and 15 are respectively side and rear elevational views oflower portionsof the door frame members and cooperating means forlocking such members to the floor of the pier, in normal door-supportingposition, Figure 14 being a detail, partly in section, along lines Il-I4 of Figure 15. e f

Referring now to the drawings in detaiLin which like characters ofreference are employed to designate similar parts in the severalv views,the door embodies an upper'section l, which may be provided with lights8, and 'a lower section 9, preferably of a paneled or other solidconstruction, the two sections. being rectangular and of correspondingdimensions. Each end of the upper door-section is faced with a channelmember IE}, extending from the top to the bottom thereof, which. coactswith the flange H of the angle piece l2 fixed to the adjacent end of thelower door-section to maintain the two door-sections in association forliding movement of the lower section relatively to the upper one, ashereinafter described, the lower edge of the upper door-sectionoverlapping the upper edge of the lower section, when the two sectionsare in their closure-forming position (see Figure 4).

Mounted on a laterally extending shaft l3 on each end of the upperdoor-section, adjacent the top edge thereof, is a roller l4, while aroller 15 is rotatably supported from a fitting l6 fixed to each of theends of the lower door-section, at the base thereof, to locate theroller lioutwardly of the face of the doorsection, with its axisparallel thereto (see Figure 9). These rollers 14 and I5, are adapted tobe entered in and traverse the tracks or guideways 18 and 19 which formthe opposite vertical side members of a doorway frame, the upper ends ofsaid members being aligned with the contiguous end of the curvedcontinuation 20 of the door track 2|, supported parallel to the ceilingof the pier shed, as by suitable hangers, generally indicated at 22 and23.

The aforesaid'guideways may comprise single channels of the appropriatewidth and depth, or each may be formed by utilizing two shallow channelsassembled in parallel, with their flanges in oppositely spaced relation,as at [8a and 18b, the channels being rigidly connected by a series ofvertically spaced tie plates 180, the outer surface of the web of thechannel 18a forming the outer face of the frame member of which it is acomponent, as clearly shown in Figure 14. Obviously, the formation ofthe vertical frame members in this manner provides a lighter and moreeconomical construction, without sacrificing strength'or rigidity.

As will be evident, each doorway or opening includes the fixed header24, formed by the pier wall or otherwise, and 'two vertical side-formingmembers It and I9, the upper door-section I normally being in alignmenttherewith, while the 'lower'door-section 9 is disposed to the'rear orinwardly thereof, with their abutting edges overlapped, as previouslyexplained. (Figure 4.)

Each vertical door-frame member, at its upper end is hingedly connectedto the adjacent end of the door track 2!i2 l the hinge, preferably,being of the spring type and acting to urge the frame member rearwardlyout of alignment with the end of the door track to which it is connected(see Figures 4 and 12) for the purposes which will be explained.

Supported in parallel to the pier ceiling is a track 25, extendingrearwardly from th outer wall of the pier, preferably of thecross-sectional configuration shown in Figure 13, in which is mountedfor travel a carriage 26, carrying a dependent arm 2'! terminating in abifurcated'portion 28, forming a mounting for a pulley 29. A cable 39,connected to the hinged door-frame member, adjacent its lower end, isreeved through this pulley 29 to traverse a second pulley 3| adjacentthe inner end of said track 25, forwinding upon a mechanically ormanually actuatable drum or reel 32, supported from a fixed surface, asa column 0 of the pier shed structure.

Preferably set into the floor I of the pier and appropriately anchoredthereto. is a shoe 34 adapted to cooperate with each adjacent pair ofhinged door-frame members. This shoeembodies a toe-piece 35, withparallel sides 36 and 3?, having'inclined top surfaces, the base of theshoe being provided'with'laterally spaced vertical bores or slots 38,for the reception of the slide bolts to and 4e, rigidly fastened to theweb portions of adjoining hinged door-frame mem hers is and E9, tointerlock such members with said shoe and rigidly retain them in theirnormal vertical door-supporting position, with their upper ends inalignment with the door tracks 20, 26, with which they are respectivelyconnected, as heretofore described.

It will be understood from the foregoing, that each door, embodying the'upperand lower sections 7 and 9, is locatable in closure-formingposition between a pair of appropriatelyspaced vertical doonframemembers I3 and IS, the gap therebetween corresponding approximately tothe width of a the door; also, that a vertical member l8 of onedoor-frame or opening, immediately adjoins the vertical member IQ of theframe of the adjacent doorway, such immediately adjoining frame members#8 and [9 being interloclzable with the aforementioned common shoe,independently of each other, for reasons which will become obvious.

As will be observed from Figure 3, door-section 'i is supported betweenthe cooperating vertical members '13 and 59 of the doorway and inengagement therewith, through the medium of the guide rollers I5, bytension spring ii and 52, connected by a turnbuckle l3 and located aboveand parallel to the top of said door-section,

the upper the outer ends of said springs having cables and ii: fixedthereto, which pass through grooved pulleys it and '27 and are in turnsecured to the inner faces of the respective end-forming members of saiddoor-section and centrally of -the top and bottom ,edges thereof, asindicated at t3 and 49. Each of ,the pulleys, and i? is swivelly mountedon a shaft or pin 56, horizontally sup,- portedin the lugs 51 and 52 ofth bracket 53 bolted-or otherwise secured to the pier structure, injuxtaposition to the upperend of a vertical door-frame member, forradial movement under the; guidance of its tracking cable, as the doorsections shift from one to another of their extreme positions inoperation, the aforesaid tension springs contributing to thecounteraction of inertia forces in th initiation of movement of thedoor-sections, from their extreme positions and acting to retardativelycontrol their movement to such extreme positions, as hereinafter will bemore fully explained. a

In superposed relation to the aforesaid tension springs 1i and 42 is ashaft 55, journaled in bearings 55 and 53, on one end of which is keyeda drum of a truncated conical configuration, having a spiral peripheralcable-receiving groove 58, a similar drum 5% being fixed to said shaftadjacent its other end, with which a gear til}, like: wise keyed to saidshaft, is associated, said gear being adapted to be driven from anelectric motor 6|, through suitable intermediate, gearing, generallyindicated at 62, it being understood that the latter gearing may vary tomeet installation and operatingrequirements.

A pair of "axially spaced torsion springs 63 and M, concentric with saidshaft 54, are each supported at their adjacent ends from a bracket 65attached to the pier wall onthe vertical center line of the doorway, byafitting embodying ahub portiontfi and concentric flange 6.1,longitudinally slotted; seat 68, for the reception of the end 01' thespring, as shown in Figure 6, the hubbeing bolted to the annulus 69 ofthe bracket, in spaced relation'theretojas at 10, foraxial alignment ofscribed-and the two the bore -H of-said fitting with the-bore T2 ofthe-"bearing member" ?3. Th diazm'eter of the aligned bores?! and 12 issuch'as to allow sum c'ient. tolerance for the shaft to rotate freelytherein. The endof each spring adjacent a drum is positively connectedto the shaft 5!, as by a sleeve l lpinned to the shaft, as at 15, andprovided with" an enlarged portion 7'5, slotted, gas at 'F'L'the end ofthe spring being shaped to enter said slotxandaemb'r'ace said sleeve, asshown in Figure 7, it being m'anifest'that in the rotationof the shaftinone direction, the torque of the shaft will be effective thereon tocompress oriwind the espective springs, while th rotative movement ofthe shaft in the reverse direction will be controlled in proportion tothe load and the decrease in tension of the springs as they expand orunwind. I l

The lower door-section 9 is supported and operated by means of a pair ofcables as at 18 and 79, which are connected to the end-forming membersthereof, as at 80 and 8|, approximately centrally of the top and bottomedges of the door-section, and to, the drums 51 and 59 respectively;-Any suitable meansmay be employed for anchoring the ends of the cablesextending, upwardly. to the drums in the convolutions thereof of largestdiameter, so that as the drums revolve in one direction the cables willwind in the spiral grooves thereof toward the groove of smallestdiameter, while the revolution of the drums in the reverse directionwill cause the cable to unwind or traverse the cable toward the grooveof greatest diameter, the latter rotative movementof the drums occurringwhen the doors position, during which movement the springs 63 and 64 arewoundor compressed, as hereinafter will become evident. Assumingthat thevertical door-frame memthe' floor of the pier as dedoor-sections I and 9are in closed positionwith therespective abutting edges 7 sections insuperimposed overlapped, the operation of the motor 60, through theinterconnected gearing will drive the shaft 54 to rotate the drums 51and 59, keyed thereto, initiatingthe winding of the respective cables 18and 79.150 raise the lower door section 9, its guide rollers 45traversing the tracks formed by;the,door-frame members I8 and 19 untilthe extending arms [6 at the base of said door-section impinge againstthe lower edge of springs 4| and 42, connected to the upper doorsectionbythe cables, 44 and 45 at this point contribute'to counteract theinertia of the upper door-section by generating a lifting impulse andinitiating movement of the upper door-section in unis n with the liftedlower door-section; and

seotionzwill enter the curved-portion 20 of the,

door track, while the guide rollers l5 of the lower door-section arestill engaged with the vertical side members of thedoor-frame, thelifting force continuing effective upon the lower end of the lowerdoor-section until its rollers .l5 enter the curved portion of the doortrack for the final dispositionof the superimposed door-sections inalignment with the horizontal portion of, the door-track, with therollers 14 and I5 of both sections in engagement therewith. As thedoorsection movesto this latter position, the tension springs 4| andAZagain become efiective to yieldingly retardthe movement of thedoor-sections to their extreme or final position in association withthe" horizontal track portion 2|, it being evident from Figure 5, thatas the. mated doorsections assume the position of angularity withrespect to the vertical and horizontal guideways shown in dotted lines,springs 4| and 42 will have assumed their normal degree of tension, butas the mated doors progress toward their extreme position on thehorizontal portion 2! of the door track the tension of the springs willbe gradually increased, with a concomitant increase in the resistance tothe movement of the door-section longitudinally of the track.

As has been stated, the torsion springs are compressed or wound up, asthe door-sections are lowered or moved to closing position and it may bepointed out that as the drums rotate to raise the door-sections, as justexplained, the tension of these springs decrease, as they unwind orexpand, with the raising of the lower door-section, while the weight ofthe door-section remains constant throughout its movement as a unit, itbeing evident that the decreasing efiective radius of the drums as thecables progress through the smaller diameter spirals, results in acorrespondingly decreasing leverage, which lessens the load or force ofthe door-section so that it will be counterbalanced throughout itsmovement. While the'load is greatly increased as the lowerdoor-sectionengages the upper door-section and in the initial movementof the two sections as a unit, which, to an extent is offset by theaction of the tension springs M and 42, as set forth, at this period ofoperation the cables 18 and"!!! are progressing into the minor diametergrooves or convolutions to proportionately decrease the leverage throughwhich the multiplied weight acts, so that the load which is a resultantof such weight will be properly counterbalanced by the springs 63 and64, it being manifest that as the mated door-sections approach thehorizontal the weight diminishes further, as the efiective efiortbecomes relatively negligible.

When the door-sections have been elevated to their extreme position, inthe horizontal portion Zlof the door track, as just described, thevertical door-frame members, .as desired may be swingably elevated to aposition parallel thereto, following their disconnection from the shoes34, to which they are normally bolted, by the actuation of the reels32,the winding of the cables 30 thereon, producing an upward radialmovement of the door-frame. members on their respective hinge lines, asthe carriages 26 respond to the cable movement through their dependentpulleys 29 and traverse their tracks to their ulti mate positions inproximity to the pulleys3l at the end of the tracks, with theframe-members disposedbelow and parallel to the track 25. As will beunderstood, any frame member may be raised independently of the others.For instance where onlytwo adjacent doors may be opened for a particularloading or unloading operation, the adjoining frame members 18 and I9,one forming a part of each doorway maybe raised to provide anunobstructed opening having a span equivalent to the overall width oftwo doorways, plus the width of the two doorway members that are raised.

. It is obvious that various changes and modifications may be made tothe details of construction without departing from the general spirit ofthe invention as set forth in the appended claims.

I claim:

1. In a closure for a doorway, an upper and a lower door-section, meansfor moving said lower section in a vertical path to a position insuperimposed relation to said upper section and for moving both of saidsections as a unit to an extreme open position, torsion spring meansconnected to said lower section for counter-balancing the movement ofsaid lower section and the movement of the two sections as a unit tosaid extreme open position, and tension spring means separate from saidcounterbalancing means for generating lifting efiort in the initiationof movement or" the upper section toward open position, said separatespring means being efiective in a part of the conjoint movement of thetwo sections to the latter position, to yieldingly retard such conjointmovement.

2. Ina closure for a doorway, an upper doorforming section and alower-door-forming section, tension spring means for supporting saidupper section within the doorway, in closing position, means for movingsaid lower section in a vertical path to a position in superimposedengagement with said upper section and for moving both of said sectionsas a unit from such vertical path to a horizontal position above saiddoorway, torsion spring means for counterbalancing the lower section andthe two sections as a unit in their movement to and in such horizontalposition, said upper door-section supporting spring means acting togenerate a lifting impulse effective to cushion the movement of thelower section into engagement with the upper section, for theinititation of movement of the upper section in unison with the engagingmovement of the lower section and to retard the movement of the twosections in a final stage of their actuation in said horizontalposition.

3. In a closure for a doorway, an upper doorforming section and a lowerdoor-forming section, tension spring means for supporting said uppersection within the doorway, in closing position, means for moving saidlower section in a vertical path to a position in superimposedengagement with said upper section and for moving both of said sectionsas a unit from such vertical path to a horizontal position above saiddoorway, means for guiding said sections in their vertical andhorizontal movement, including (20-,

operating fixed and relatively movable elements, torsion spring meansfor counterbalancing the lower section and the two sections as a unit intheir movement to and in such horizontal position, said upper sectionsupporting means coacting with said moving means in the engagement ofsaid upper section by said lower section to generat a lifting impulseefiective in initiating vertical movement of said upper section inunison with the movement of the lower section into engagement therewith.

4. A sliding closure for a doorway, including upper and lowerdoor-closure sections, trackways lowersection along said 'for guidingsaid sections invrvertical movement and. retaining them ing position,trackways section, said lower section being adapted to engage with andpick up said upper section for, con tinuing movement of the two sectionsas a unit,

in the sustainedoperation ofsaid moving means,

V and both sections intheir and counterbalancing torsion springs forcontrolling the movement of said sections, said 7 spring suspensionmeans reacting to the pick-up engagement of said, upper section by thelower one; to generate lifting efiort and initiate movement of saidupper door-section;

, 5. A'sliding closure for a, doorway, upper and lower door-closuresections, trackways for guidingsaid sections'in vertical movementandretaining them in cooperating closure.- forming position, trackways forguiding said sections from their vertical path. of movement to and 1in-a horizontal path of movement, tension spring includin 1 means forsuspending saidupper section between said vertical'trackways, means forelevatingsaid lower section to a position in supe p relation to saidupper section, said lower section being adapted to engage and pick upsaid upper section for continuing movement of the two sections as a unitin a continuous operation of said moving means, and counterbalancingtorsion springs efiective in controlling the movement of said sections,said spring suspension means reacting to the impelling effort applied tosaid upper section by the pick-up engagement of the lower sectiontherewith, to generate lifting efi'ort effective to decrease the loadimposed upon said lower section. I

6. A closure for a doorway, door section and a lower door for guidingsaid sections in vertical movement and retaining them in associatedclosure-forming position, trackways for guiding said sections from theirvertical path of movement toand in a horizontal path of movement,tension spring means including an upper for suspending said uppersection between said" said lower to a posivertical trackways, means formoving section along said verticaltrackways tion in superimposedrelation to said upper section, said lower section being adapted toengage with and pick up said upper section for continuing movement ofthe two sections as a unit in the continuous operation of said movingmeans and ccunterbalancing torsion springs associated with said movingmeans for controlling the movement of said sections, said springsuspension means coacting with said counterbalancing springs in responseto the impact of the pick-up engagement of the lower door-section withthe upper one to overcome the inertia forces and main constant thelifting effort produced by said moving means.

'7. In a closure for a doorway, an upper doorforming section and a lowerdoor-forming section, tension means for supporting said upper section ina closure-forming position in the doorway, and for generating a liftingimpulse in the initiation of movement of said upper section, means formoving said lower section in a vertical path to a position insuperimposed relation to said upper section and for moving both of saidsections as a unit in and from such vertical path to a horizontalposition above said doorway,

section, trackways and from the I vertical to position; saidside-defining members being movwhen said sections are from theirappropriately laterally guiding the movement of said sections verticallythe aforesaid, horizontal able relative to the guiding portionsthereabove in association with-said latter portions, and torsion, springmeans connected to said lower. section for counterbalancing saidlowersection; in its individual movement conjoining movement to and in:such horizontaljposition; V, l

sliding door" construction, including a doorway havin relativelyvertically spaced permanent surfaces, definingthebase and head thereof,and, vertical side-definlngmembers in laterally spaced relationinormally locatabie between said vertically spaced surfaces, means havingportions calmed with su ported parallel ;to the head, surface, vsaidsaid vertical members members being connected to such alined portionsfor relative movement, devices for detachably interlocking said verticalmembers with said base surface, said members being adapted to cooperatewith sal means to form and lower door-forming sections associatedtherewith forsliding movement to a vertical closurejdorming p sitionandto a position in association with said means and independent of saidvertical members to open said doorway, as defined by said head and basesurfaces and said members, said vertical members being shiftable saiddoor-section guiding positions to locate-them above said doorwayhead-defining surface, whereby the normal rectilineal outline of'thedoorway will be interrupted.

9, A sliding door construction, including a doorway formed by relativelyvertically spaced ous guideways for the movement of door-formingsections associated with said members to and from open and closedpositions,'and means for actuating said vertical members to theaforesaid horizontal position when such door-forming sections aredisassociated therefrom and associated with said supporting members.

10. A doorway formed by relatively vertically spaced permanent surfaces,defining the head and base thereof and side-defining members in spacedrelation, said members being hingedly mounted in juxtaposition to saidhead-forming surface for movement from their doorway-side-formingpositions to a horizontal position in association with said headformingsurface, means carried by said members for detachably connecting saidmembers to said base surface to retain them in their doorway framedefining positions and means for elevating said members to saidhorizontal position, when disconnected from said base member, to

means, including members defining the sides of the doorway and alinedportions the-reabove, said In'embers and saidlalined portions coastingfor uideways. for upper adapted to coact disrupt the rectilineal outlineof said doorway, normally formed by said head and top surface and saidside-defining members cooperating therewith.

11. A sliding door construction, including a doorway formed byrelatively vertically spaced permanentsurfaces, defining the head'andbase thereof, and side defining members in laterally connected to saidalined means," and means for actuating said members on said hingeconnections to-raise them to a position substantially parallel to saidalined guideway continuationforming means, when the door-formingsections are supported horizontally from said latter means. s 7

12. In a closure for a doorway, an upper and a lower closure-formingsection, trackways for up said upper guiding said sections in verticalmovement and retaining them in associated closure-forming position, withabutting portions thereof overlapped, trackways having portions alinedwith said vertical trackways and conformed'to guide said-door sectionsfrom their vertical path of movement'to and in a horizontal path ofmovement, tension spring means functioning as the sole support of saidupper section between said vertical trackways, means comprising aconical drum-and cable assembly for moving said lower section fromclosure-forming position longitudinally of said vertical trackways to aposition in superimposed relation to said upper section, said lowersection being adapted to engage and pick section from itsclosure-forming position for continuing-movement of the two sections asa unit between said vertical trackways to a position in arrestedsupported engagement with said horizontal trackways to clear saiddoorway, and counterbalancing torsion spring means connected to saidlower door section effective in controlling the movement of saidsectionsin their transposition from doorway closing to doorway openingpositions, said vertical trackway members bein displaceable at will fromtheir guideway forming positions'when said door-forming sections arehorizontally supported;

' NATHAN MICHELMAN.

